Carpoint 4 pin standard 12 Volt relay with on/off function to switch a heavy energy consumer with up to 30 Amps with a small or sensitive switch. The relay has 4 connections; Input control current (switch), output control current (ground), input main current (power supply) and output main current (accessory). Always disconnect the minus (-) before installing the relays and make sure that the power wires are fused.